Coolant leak - thermostat housing ?

[Smite007]

Hi
Got a coolant leak on the passenger side front. Will this be from the thermostat housing?

I’ve replaced the coolant bottle cap as that looked in poor condition.

Temp goes up to just under 90, after a few minutes I can hear two releases of liquid (like a squirt) and the temp drops to 0 then builds back up to 90. It does this cycle twice and then sits at 75ish to 90.

temp doesn’t go past 90 but after a few short journeys I get the low coolant warning due to the amount leaking.

No white smoke, no mayo substance in the oil cap or dipstick and runs normal so don’t think it’s the head gasket. Passenger footwell is dry as well where the matrix is.

2010 1.6 THP 200

 

[RCZKam]

Passenger side leak and wayward temp readings point towards thermostat, they are prone to cracking and leaking. Have a search on here. I know you have checked but are you absolutely sure it’s coolant and not oil, fuel etc

I’m running an auto so I’m guessing your picture is of the manual gearbox housing?

Its not a massive job if you can wield a spanner or two but you have to make sure you order the correct thermostat as it was updated once or twice, there is a handy guide done by a member on here - Thermostat housing replacement

Good luck

 

[RCZKam]

Unfortunately for the part numbers you never know what you are getting online. I’ve come across three different variants (there might be one more)

Here below you can see all three have bleeds screws but two have coolant sensors mounted externally but in different places (two separate 2 pin plugs) and the other one has it mounted internally (single 4 pin plug)



Please excuse the child like handwriting!

You can buy an adaptor harness if you do change from a single 4 pin to two seperate 2 pins

 

[Pedro]

I fitted this a few weeks ago off ebay Mine is the 200 you remove the bleed screw to insert the temp sensor probe wiring harness very easy job as Kam says

 

[Pedro]

I fitted this a few weeks ago on a 200 View attachment 14315

 

[Smite007]

Thanks for the replies guys

I fitted this a few weeks ago off ebay Mine is the 200 you remove the bleed screw to insert the temp sensor probe wiring harness very easy job as Kam says View attachment 14315

Thanks mate - I’ve have a look at that one

 

[Smite007]

Passenger side leak and wayward temp readings point towards thermostat, they are prone to cracking and leaking. Have a search on here. I know you have checked but are you absolutely sure it’s coolant and not oil, fuel etc

I’m running an auto so I’m guessing your picture is of the manual gearbox housing?

Its not a massive job if you can wield a spanner or two but you have to make sure you order the correct thermostat as it was updated once or twice, there is a handy guide done by a member on here - Thermostat housing replacement

Good luck

Hi

Yes it’s just the coolant, fully pink.
Yeah that’s the gear box housing on the left hand side and the leak appears to be coming from the space above / to the right of the gear box housing. I think this is where the thermostat is located?

 

[RCZKam]

Hi

Yes it’s just the coolant, fully pink.
Yeah that’s the gear box housing on the left hand side and the leak appears to be coming from the space above / to the right of the gear box housing. I think this is where the thermostat is located?

Gearbox on the right hand side as you stand in front of the car? Yes thermostat, it’s underneath your battery to the left of it (again standing in front)

Little tip, the thermostat is held in with 3 fixings as below, remember where they are as you’ll be needing an extension on your ratchet. On mine the top was a 10mm nut and the two lower ones 8mm bolts? Just incase your sitting there spinning a 10mm all day wondering why nothing’s happening





And don’t be too aggressive pulling the thermostat away after you have removed a large C clip on the end of the large elbow of the thermostat which sits inside a fixed metal coolant pipe running across the back of the engine to the water pump, I found holding the metal pipe with one hand and gently levering the thermostat housing away and off to be less caveman as you do not want that metal pipe to become loose or disjointed or you will have a leak at the other end which means inlet manifold off unless you can play with spanners with your eyes closed

Good luck

 

[Pedro]

Depending on the state of the Hose ends I apply silicone grease around all the inlets including the elbow & they just all slide together nicely the other one to watch for is the Turbo feed pipe that should be removed as a caution if this gets damaged it may be a scrap car or dealer part only?

 

[RCZKam]

Depending on the state of the Hose ends I apply silicone grease around all the inlets including the elbow & they just all slide together nicely the other one to watch for is the Turbo feed pipe that should be removed as a caution if this gets damaged it may be a scrap car or dealer part only?

Pedro - is that turbo pipe replaced at the upper end with a new O ring? I just reused the old one but you got me thinking now

Silicone grease good shout

 

[Pedro]

No the banjo union on the Turbo hose is normally fine as long you ensure the copper washer is not damaged on refit should be ok